Tamper evident closures of various types are well known. One type of tamper evident closure comprises a tamper evident ring. Tamper evident closures with tamper evident rings are used for bottles and other containers with closures that generally have a diameter of about 5 to 6 centimeters or less, such as bottles or tubes for tablets, especially effervescent tablets. European Patent No. P 0 202 506, for example, discloses a container with a closure comprising a tamper evident ring.
Tamper evident closures known in the art may also comprise a tamper evident tab that may be on one side of the closure and be connected to the lid and the body of a tube, container or package by a tear-off and tamper evident web. The tab must be removed before opening the closure. Tamper evident tabs are often used for plastic, large diameter (more than 5 to 6 cm) cup-like packages with a lid.
Tamper evident tabs may be used with tubes as in French Patent No. 2,707,958 and Japanese Application No. 2004/175,436. Tamper evident tabs are readily apparent to the consumer, and a consumer may easily perceive whether the tamper evident closure has been broken or manipulated. This determination is harder with the tamper evident ring. In addition, it is easier to peel off a tamper evident tab than to break apart a tamper evident ring.
Although tabs have certain advantages, they also have certain drawbacks. If a tamper evident tab has been removed it is not always clear that the tube, container or package has actually been opened. Consumers might therefore unnecessarily reject or discard a tube, container or package, simply because the tab had been removed, even though the tube, container or package had not, in fact, been opened.
Tamper evident rings do not snap off the packaging as readily as tabs. But, it is easier for consumers to miss the fact that the ring has become detached from the packaging. Thus, a tamper evident ring might not protect the consumer if the tube, container or package had been opened. Another disadvantage of tamper evident rings is that the tamper evident ring can fall down the tube, container or package when the tear-off and tamper evident webs connecting the ring to rest of the packaging are broken.
Neither tabs nor rings, acting alone, have proven to be fully adequate to warn consumers of tampering without the false positive of missing or damaged tabs or the potential false negative of an overlooked detached ring.